Peri-implantitis in a specialist clinic of periodontology. Clinical features and risk indicators.

Implant therapy has become a widely recognized treatment alternative for replacing missing teeth. Several long term follow-up studies have shown that the survival rate is high. However, complications may appear and risk indcators associated with early and late failures have been identified. The purpose of the present retrospective clinical study was to describe some clinical features of patients with clinical signs of peri-implantitis and to identify risk indicators of peri-implantitis in a population at a specialist clinic of Periodontology. In total,the material consisted of 377 implants in 111 patients with the diagnosis peri-implantitis. The mean age at the examination was found to be 56.3 years (range 22-83) for females and 64.1 years (range 27-85) for males. The mean number of remaining teeth was found to be 10.5 (S.D. 8.89) and the mean number of implants was 5.85 (S.D. 3.42). For a majority of the subjects, more than 50% of the remaining teeth had a marginal bone loss of more than 1/3 of the root length. Forty-sex percent of the patients visited regularly dental hygienists for supportive treatment. The percentage of implants with peri-implantitis was significantly increased for smokers compared to non-smokers (p = 0.04). In the group of non-smokers, 64% of the implants had the diagnosis peri-implantitis, while the corresponding relative frequency for smokers was 78%. A majority of the individuals had a Plaque index and Bleeding on probing index >50%. The median of the follow-up time after implant placement was 7.4 years and the observation period was not significantly correlated to the degree of bone loss around the implants. Among the subjects with a mean bone loss >6 mm at implants with peri-implantitis, more than 70% had a mean marginal bone loss > 1/3 of the root length of the remaining teeth. A positive and significant correlation was found between the degree of marginal bone loss in remaining teeth and the degree of bone loss around implants with peri-implantitis. In conclusion, the results of the present study indicate that smoking as well as previous history of periodontitis are associated with peri-implantitis and may represent risk factors for this disease.